The Anal Glands of the Aphodiinae. 



By Dr. L. Boedas. 



The anal glands of the Aphodiinae differ essentially in their form and 

 situation, and above all in their structure, from those of the other 

 Coleoptera. While these organs generally consist either of a series of 

 small spheres disposed in clusters, or of two long appendicular tubes 

 (Dytiscidae, Gyrinidae), those of the Aphodiinae (Aphodiusfossor S L.), 

 on the contrary, consist of a series of unicellular secretory acini- — 

 spherules provided with a very delicate canaliculus ending in an 

 efferent cylindrical duct. This disposition reminds one of the form 

 which obtains in the glands we have described in the Hymenoptera 

 (Apinae and Bombinae), under the name of supracerebral glands (see 

 Ann. Set Nat. [Zool.], 1894; "Appareil Glandulaire des Hymenop- 

 teres," Plate 1, Figs. 10, 11, and 15). 



The anal glands are paired and open separately at two points very 

 near each other on the basilar plate immediately under the chitinous 

 case that constitutes the principal piece of the genital armature. 



Each gland is composed of a multitude of unicellular acini, 

 disposed in groups along the principal excretory duct of each gland. 

 Those acini are generally spherical, and contain an internal granular 

 protoplasm with a few peripheral vacuoles. 



The nucleus that lies near the centre of each cell encloses several 

 nucleoli. A very thin membrane surrounds each acinus, and is con- 

 tinued into an excretory canaliculus which is short and very thin. 

 This canaliculus takes origin by several branches at the centre of the 

 acinus. All the canaliculi open directly into two uniformly cylindrical 

 tubes, which may be designated the excretory canals of the gland. 

 There is no collecting reservoir as in the other cases. There is, there- 

 fore, as this short summary indicates, a quite special structure in this 

 particular case. For further details I must refer to my memoir on 

 the defensive glands of insects. 



Marseille. 



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